RU2792949C2 - Lidar system and coherent detection method - Google Patents

Abstract

FIELD: lidar systems.

SUBSTANCE: technology relates to light detection and ranging systems (LiDAR, Light Detection and Ranging) in general and, in particular, to systems and methods for scanning the environment using coherent detection. Lidar system with time-of-flight measurement contains a laser source that emits a light beam in a narrow band, a fast-switching module that emits short pulses of the light beam along the first optical path, and the remaining part of the light beam - along the second optical path, a scanning unit that emits short pulses. in the direction from the system to the surrounding objects, at least one optical element that combines the residual light in the second optical path and the signal reflected into the system from the surrounding objects, a detection unit that receives the combined signal, and a controller that processes electronic signals from the detection unit received from the combined signal, and determining the distance to at least one of the surrounding objects by determining the time of flight calculated by processing the electronic signals obtained from the combined signal.

EFFECT: improving the quality of weak signals in the lidar system while limiting the output power of the light source of the lidar system.

13 cl, 5 dwg

Description

The technical field to which the invention belongs

[001] The present technology relates to light detection and ranging systems (LiDAR, Light Detection and Ranging) in general and, in particular, to systems and methods for scanning the environment using coherent detection.

State of the art

[002] Lidar systems (light detection and ranging systems), also called lidars, are widely used in unmanned (autonomous) vehicles. Lidar systems measure distances between the system and surrounding objects by illuminating the environment with light and collecting light reflected from one or more objects in the surrounding space.

[003] In a typical time-of-flight (ToF) lidar system, the light source emits multiple pulses of narrow laser beams in the field of view. Light reflected and/or scattered from an object in the field of view is received by the detection unit of the lidar system to determine the position of that object. For such ToF systems, the distance to an object is determined by measuring the time interval between the moment a light beam is emitted and the moment a reflected and/or scattered light beam is detected.

[004] The reflected beams received by the lidar are processed to generate data points using a central computer, with each beam pulse corresponding to one data point in a point cloud representing the surrounding objects in the form of a 3D map. The 3D map appears to be more or less detailed and accurate depending on the density or update rate of the point cloud. Generally, the higher the sampling rate in the field of view, the more detailed and accurate the 3D map is.

[005] Depending on various environmental factors of the vehicle being scanned by the lidar system (eg, environmental conditions), the reflected and scattered light detected when measuring the distance to surrounding objects may sometimes be weak. Processing of weak signals is difficult due to noise on the 3D map or false detection. In some cases, the power of the light pulses emitted by the system (i.e. illumination or intensity) can be increased, but the maximum power of the light pulses emitted is limited, for example, for safety reasons for human eyes. Also, increasing output power does not always eliminate noise problems.

Disclosure of invention

[006] Thus, there is a need for systems and methods to circumvent, reduce or overcome the limitations of the prior art.

[007] In accordance with broad aspects of the present technology, a time-of-flight lidar system using coherent detection for improved environmental scanning is implemented. To amplify weak reflected or scattered signals from the environment in a lidar system, in at least some non-limiting embodiments of the present technology, a portion of the narrow wavelength laser light generated by a light source of the lidar system is directed to a detection unit for optical interaction with reflected from surrounding objects by signals in order to detect weak incoming signals using the coherent detection method. In particular, a continuous wave light beam emitted by a light source is divided by a fast switching module (for example, an acousto-optic modulator or an electro-optical modulator) into two beams - the first beam is narrow light pulses, and the second beam is the residual original light beam (minus pulses directed to the first ray). With the first beam of pulses, the scanning unit scans the field of view of the system. The second beam is sent to the detection unit, where it interacts with the incoming light beam reflected from the surrounding objects. The weak signals can then be detected at the detection unit by measuring the interference signal at the detector using conventional coherent (heterodyne or homodyne) detection techniques. In this way, weaker reflected signals can be detected by reducing the noise level in the data without the need to increase the power of the output beam too much.

[008] In accordance with the first broad aspect of the present technology, a time-of-flight lidar system is implemented, comprising a laser source configured to emit a light beam in a narrow band, a fast switching module configured to receive a light beam from a laser source and modulate the amplitude of the light beam for emitting short pulses of the light beam along the first optical path and the residual light of the light beam along the second optical path, a scanning unit located on the first optical path and configured to scan with short pulses of the light beam in the direction from the system to the surrounding objects, at least one an optical element configured to combine the residual light of the light beam in the second optical path and the signal reflected into the system from surrounding objects into one signal, a detection unit configured to receive this combined signal, and a controller connected with the possibility of communication with the detection unit and configured to process the electronic signals from the detection unit obtained from the combined signal and determine the distance to at least one of the surrounding objects based on the time of flight calculated when processing the electronic signals obtained from the combined signal.

[009] In some embodiments, at least one optical element is a beam splitter.

[010] In some embodiments, the fast switching module is an acousto-optic modulator.

[011] In some embodiments, the implementation of the controller determines the time of flight method of heterodyne detection.

[012] In some embodiments, the system is a fiber optic system, and at least one optical element is a fiber optic splitter.

[013] In some embodiments, the detection unit includes a photodetector communicatively connected to the controller.

[014] In some embodiments, the detection unit includes a first photodetector and a second photodetector, each of which is capable of receiving at least a portion of the combined signal.

[015] In some embodiments, the system further comprises an optical amplifier operatively located between the fast switching module and the scan unit and configured to amplify the intensity of the short pulses of the light beam.

[016] In some embodiments, the fast switching module is an electro-optical modulator.

[017] In accordance with the second broad aspect of the present technology, a method for controlling an optical system is implemented, including initiating, by a controller, a laser source to emit a light beam in a narrow band; controller control of a fast switching module to modulate the amplitude of the light beam emitted in at least two directions - short pulses of the light beam and residual light of the light beam, initiating by the controller of the scanning unit to scan with short pulses of the light beam in the direction from the system to the surrounding objects, receiving by the controller electronic signals from the detection unit receiving the combined signal, which is a combination of the residual light of the light beam from the light source and the signal reflected into the system from the surrounding objects, and the controller determines the distance to at least one of the surrounding objects based on the time of flight calculated by processing electronic signals derived from the combined signal.

[018] In some embodiments, control of the fast switching module includes control of the acousto-optic modulator by the controller.

[019] In some embodiments, determining the time-of-flight controller includes determining the time-of-flight by heterodyne detection.

[020] In some embodiments, the method further includes causing the controller to amplify the intensity of the short pulses of the light beam with an optical amplifier, the optical amplifier being operatively placed between the fast switching module and the scanner.

[021] As used herein, the term "light source" broadly refers to any device for emitting radiation, such as an emitted signal in the form of a beam, such as a beam of light, including radiation at one or more appropriate wavelengths in the electromagnetic spectrum. In one example, the light source may be a laser. Thus, the light source may comprise a laser such as a solid state laser, a laser diode, a high power laser, or an alternative light source such as a light emitting diode (LED) light source. Some non-limiting examples of a laser source include fairly narrow spectrum lasers, a Fabry-Perot diode laser, a quantum well laser, a distributed Bragg reflector (DBR) laser, a distributed feedback laser (DFB). ), fiber optic laser, or vertical cavity surface emitting laser (VCSEL). In some non-limiting examples, the laser source may include a laser diode that emits light at a wavelength from about 650 nm to about 1150 nm. In addition, the light source may comprise a laser diode emitting light at a wavelength of about 800 nm to about 1000 nm, about 850 nm to about 950 nm, about 1300 nm to about 1600 nm, or any other suitable range. Unless otherwise indicated, the term "approximately" in relation to a numerical value is defined as a deviation of up to 10% from the specified value.

[022] In the context of the present description, the "output beam" can also be referred to as an emitted beam, such as a beam of light generated by a radiation source and directed from the source to the region of interest. The output beam may have one or more parameters, such as beam duration, beam angular dispersion, wavelength, instantaneous power, photon density at different distances from the light source, average power, beam power intensity, beam width, beam repetition rate, beam sequence, pulse duty cycle, wavelength, phase, etc. The output beam may be unpolarized or randomly polarized, may not have a specific or fixed polarization (eg, the polarization may change over time), or may have a specific polarization (eg, linear, elliptical, or circular polarization).

[023] In the context of the present description, the "input beam" is the radiation or light that usually enters the system after reflection from one or more objects in the region of interest. The input beam may also be referred to as the emitted beam or light beam. By reflection is meant that at least a portion of the output beam incident on one or more objects in the region of interest is reflected from that one or more objects. The input beam may have one or more parameters, such as time of flight (time from the moment of emission to the moment of reception), instantaneous power (for example, power signature), average power over the entire reflected pulse, distribution of photons in the signal over the period of the return pulse, etc. d. Depending on the particular implementation, the radiation or light collected in the input beam may come from sources other than the source of the reflected output beam. For example, some portion of the input beam may contain light noise from the environment (including stray sunlight) or from other light sources external to the system.

[024] As used herein, the term "environment" of a vehicle refers to the area or volume around that vehicle, including the portion of its current environment, available for scanning using one or more sensors mounted on that vehicle, for example, to create a three-dimensional maps of such an environment or to detect objects in it.

[025] As used herein, a "region of interest" may broadly include a portion of the observed environment of a lidar system in which one or more objects may be detected. It should be noted that the area of interest around the lidar system can be affected by various conditions, such as the orientation of the lidar system (e.g., the direction of the optical axis of the lidar system), the position of the lidar system in relation to the environment (e.g., height above the ground, the surrounding terrain, and obstacles). ), operating parameters of the lidar system (e.g. radiation power, calculation parameters, certain operating angles), etc. The region of interest of the lidar system can be determined, for example, by specifying an angle or a solid angle. In one example, the region of interest can also be defined within a given range (eg, up to 200 m).

[026] In the context of the present description, the term "server" means a computer program executed by appropriate hardware and capable of receiving requests (for example, from electronic devices) via a network and fulfill these requests or initiate their execution. The corresponding hardware may be implemented as a single physical computer or a single computer system, which is not essential to the present technology. In the present context, the expression "server" does not mean that every task (e.g. received command or request) or some specific task is received, executed or initiated by the same server (i.e. the same software and/or hardware ). This expression means that any number of software or hardware can receive, send, execute or initiate the execution of any task or request or the results of any tasks or requests. All of these software and hardware may be a single server or multiple servers, both of which are meant by the expression "at least one server".

[027] In the context of the present description, the term "electronic device" means any computer hardware capable of executing programs suitable for solving the task. In the context of the present description, the term "electronic device" implies that the device can function as a server for other electronic devices, but this is not necessary for the present technology. Thus, some (non-limiting) examples of electronic devices include self-driving devices, personal computers (desktops, laptops, netbooks, etc.), smartphones and tablets, and network equipment such as routers, switches and gateways. It should be understood that in the present context, the fact that a device functions as an electronic device does not mean that it cannot function as a server for other electronic devices.

[028] In the context of the present description, the expression "information" includes information of any kind or type that can be stored in a database. Such information includes, but is not limited to, visualizations (such as maps), audiovisual works (such as images, films, sound recordings, presentations, etc.), miscellaneous data (such as location data, weather data, traffic, numerical data, etc.), text (for example, opinions, comments, questions, messages, etc.), documents, spreadsheets, etc.

[029] In the context of the present description, the term "database" means any structured set of data, regardless of its specific structure, database management software or computer hardware for storing this data, using them or providing them with use in another way. The database may reside on the same hardware as the process for storing or using the information stored in the database, or the database may reside on separate hardware such as a dedicated server or multiple servers.

[030] In the context of the present description, the numerals "first", "second", "third", etc. are used only to indicate the difference between the nouns to which they refer, and not to describe any specific relationship between these nouns. In addition, as occurs herein in another context, reference to a "first" element and a "second" element does not exclude that the two elements may in fact be the same element.

[031] Each embodiment of the present technology relates to at least one of the above goals and/or aspects, but not necessarily all of them. It should be understood that some aspects of the present technology, associated with an attempt to achieve the above goal, may not meet this goal and/or may meet other goals not explicitly mentioned here.

[032] Additional and/or alternative features, aspects, and advantages of embodiments of the present technology are contained in the following description, the accompanying drawings, and the claims.

Brief description of the drawings

[033] These and other features, aspects and advantages of the present technology are explained in the following description, in the appended claims and in the following drawings.

[034] In FIG. 1 is a diagram of an example computer system for implementing some non-limiting embodiments of the present technology.

In FIG. 2 is a diagram of a networked computing environment suitable for use with certain non-limiting embodiments of the present technology.

[036] In FIG. 3 is a diagram of a lidar system implemented in accordance with some non-limiting embodiments of the present technology.

[037] In FIG. 4 schematically shows two beam paths of the lidar system shown in FIG. 3.

[038] In FIG. 5 is a flow diagram of a method implemented in accordance with some non-limiting embodiments of the present technology.

[039] It should be noted that the drawings are not to scale unless otherwise indicated.

Implementation of the invention

[040] The examples and conventions presented herein are intended to provide a better understanding of the principles of the present technology, and not to limit its scope to such specifically given examples and terms. It should be understood that those skilled in the art are capable of developing various methods and devices that are not explicitly described or shown, but that implement the principles of the present technology within its spirit and scope.

[041] In addition, to facilitate a better understanding, the following description may contain simplified implementations of the present technology. Those skilled in the art will appreciate that various embodiments of the present technology can be significantly more complex.

[042] In some cases, useful examples of modifications to the present technology are provided. They contribute to understanding, but also do not define the scope or boundaries of the present technology. The presented list of modifications is not exhaustive and the person skilled in the art can develop other modifications within the scope of this technology. In addition, if modifications are not described in some cases, this does not mean that they are impossible and / or that the description contains the only possible implementation of one or another element of the present technology.

[043] The description of principles, aspects, and embodiments of the present technology, as well as their specific examples, are intended to cover their structural and functional equivalents, whether they are currently known or will be developed in the future. For example, those skilled in the art will appreciate that any block diagrams described herein correspond to conceptual representations of illustrative circuit diagrams embodying the principles of the present technology. It should also be understood that any flowcharts, process diagrams, state transition diagrams, pseudocodes, and the like. correspond to various processes that may be represented on a computer-readable physical storage medium and may be performed by a computer or processor, whether such a computer or processor is explicitly shown or not.

[044] The functions of the various elements shown in the illustrations, including any functional block designated as "processor", can be implemented using specialized hardware, as well as hardware capable of executing the corresponding software. If a processor is used, its functions may be performed by one dedicated processor, one shared processor, or several separate processors, some of which may be shared. In addition, explicit use of the term "processor" or "controller" should not be construed as referring solely to the hardware capable of executing the software and may refer to, but is not limited to, digital signal processor (DSP) hardware, network processor, ASIC (ASIC), Field Programmable Gate Array (FPGA), Software ROM, RAM and NVRAM. Other general purpose and/or custom hardware may also be contemplated.

[045] Software modules, or simply modules that are intended to be implemented in software, may be represented here as any combination of flowchart elements or other elements indicating the steps of a process and/or containing a textual description. Such modules may be implemented in hardware, as shown or implied.

[046] In the following, in view of the principles set forth above, some non-limiting examples are discussed illustrating various embodiments of aspects of the present technology.

[047] Computer system

[048] In FIG. 1 is a diagram of a computer system 100 suitable for use in some implementations of the present technology. Computer system 100 includes various hardware elements including one or more single or multi-core processors collectively represented by processor 110, a solid state drive 120, and memory 130, which may be random access memory or any other form of memory.

[049] Communication between elements of computer system 100 may be via one or more internal and/or external buses (not shown), such as a PCI bus, USB bus, IEEE 1394 FireWire bus, SCSI bus, Serial-ATA bus, etc. to which various hardware elements are electronically connected. In accordance with embodiments of the present technology, the solid state drive 120 stores program instructions suitable for loading into memory 130 and execution by processor 110 to determine the presence of an object. For example, software instructions may be included in a vehicle control application executed by processor 110. It should be noted that computer system 100 may include additional and/or optional elements (not shown), such as network communication modules, location modules, etc. .d.

[050] Network Computing Environment

[051] In FIG. 2 depicts a networked computing environment 200 suitable for use with certain non-limiting embodiments of the present technology. Networked computing environment 200 includes an electronic device 210 associated with vehicle 220 and/or associated with a user (not shown) that is associated with vehicle 220 (eg, a driver of vehicle 220). The networked computing environment 200 also includes a server 235 that communicates with the electronic device 210 via a communication network 240 (eg, the Internet, etc., as described in more detail below).

[052] In some non-limiting embodiments of the present technology, networked computing environment 200 may include a GPS satellite (not shown) transmitting and/or receiving a GPS signal to electronic device 210. It should be understood that the present technology is not limited to GPS system and may use a location technology other than GPS. It should be noted that the GPS satellite may not be available at all.

[053] The vehicle 220 with which the electronic device 210 is associated may be any recreational or other vehicle, such as a personal or commercial vehicle, truck, motorcycle, or the like. While vehicle 220 is depicted as a ground vehicle, this is not required for all non-limiting embodiments of the present technology. For example, in some non-limiting embodiments of the present technology, vehicle 220 may be a waterborne vehicle, such as a boat, or an aircraft, such as a drone.

[054] Vehicle 220 may be user driven or an unmanned vehicle. In some non-limiting embodiments of the present technology, it is contemplated that vehicle 220 may be implemented as an unmanned vehicle. It should be noted that this does not impose any restrictions on the specific parameters of the vehicle 220, such as vehicle manufacturer, vehicle model, vehicle year, vehicle weight, vehicle dimensions, vehicle weight distribution, area vehicle surface, vehicle height, transmission type (for example, two or four wheel drive), tire type, brake system, fuel system, mileage, vehicle identification number and engine displacement.

[055] According to the present technology, no restrictions are imposed on the implementation of the electronic device 210. For example, the electronic device 210 may be implemented as a vehicle engine control unit, a vehicle central processing unit, a vehicle navigation device (eg, TomTom™, Garmin™), a tablet, a personal computer built into the vehicle 220, etc. . It should be noted that the electronic device 210 may or may not be associated with the vehicle 220 in a permanent manner. Additionally or alternatively, the electronic device 210 may be implemented in a wireless communication device such as a mobile phone (eg, smartphone or cordless phone). In some embodiments, the electronic device 210 includes a display 270.

[056] Electronic device 210 may include some or all of the elements of computer system 100 shown in FIG. 1, depending on the particular embodiment. In some embodiments, the electronic device 210 is an on-board computer and includes a processor 110, a solid state drive 120, and a memory 130. In other words, the electronic device 210 includes hardware and/or application software and/or firmware, or a combination thereof, for processing data, as described in more detail below.

[057] In some non-limiting embodiments of the present technology, communications network 240 is the Internet. In alternative non-limiting embodiments of the present technology, communications network 240 may be implemented as any suitable local area network (LAN, Local Area Network), wide area network (WAN, Wide Area Network), private communications network, and the like. It should be understood that the embodiments of the communications network 240 are for illustrative purposes only. The implementation of a communication link (not specifically indicated) between electronic device 210 and communications network 240 depends, among other things, on the implementation of electronic device 210. By way of example, and not limitation, in those non-limiting embodiments of the present technology where electronic device 210 implemented as a wireless communication device such as a smartphone or a navigation device, the communication link may be implemented as a wireless communication link. Examples of wireless links may include, but are not limited to, a 3G network link, a 4G network link, and the like. Communication network 240 may also use a wireless connection to server 235.

[058] In some embodiments of the present technology, server 235 is implemented as a computer server and may contain some or all of the elements of computer system 100 shown in FIG. 1. In one non-limiting example, server 235 is implemented as a Dell™ PowerEdge™ server running the Microsoft™ Windows Server™ operating system, but it may also be implemented using any other suitable hardware, application software, and/or or firmware, or a combination thereof. In the non-limiting embodiments of the present technology shown, server 235 is a single server. In other non-limiting embodiments of this technology, the functions of the server 235 may be distributed among multiple servers (not shown).

[059] In some non-limiting embodiments of the present technology, processor 110 of device 210 may be in communication with server 235 to receive one or more updates. Such updates may include, but are not limited to, software updates, map updates, route updates, weather updates, and the like. In some non-limiting embodiments of the present technology, processor 110 may also send some operational data, such as routes travelled, traffic data, performance data, and so on, to server 235. Some or all of such data transmitted between vehicle 220 and server 235 may be encrypted and/or anonymized.

[060] It should be noted that the electronic device 210 may use various sensors and systems to collect information about the environment 250 of the vehicle 220. As seen in FIG. 2, vehicle 220 may be equipped with multiple sensor systems 280. It should be noted that various sensor systems from the plurality of sensor systems 280 may be used to collect various kinds of data about the environment 250 of the vehicle 220.

[061] In one example, the plurality of sensor systems 280 may comprise various optical systems, including but not limited to one or more camera-type sensor systems that are mounted on vehicle 220 and coupled to processor 110 of electronic device 210. In general, one or more camera-type sensor systems may collect image data about various parts of the environment 250 of vehicle 220. In some cases, image data provided by one or more camera-type sensor systems may be used by electronic device 210 in performing object detection procedures. For example, electronic device 210 may feed image data provided by one or more camera type sensor systems to an object detection neural network trained to locate and classify potential objects in environment 250 of vehicle 220.

[062] In another example, a set of sensor systems 280 may include one or more radar-type sensor systems that are mounted on vehicle 220 and associated with processor 110. In general, one or more of the radar-type sensor systems to collect data about various parts environment 250 of vehicle 220 may use radio waves. For example, one or more radar-type sensor systems may collect radar data about potential objects in the environment 250 of vehicle 220. This data potentially represents the range of objects from the radar-type sensor system, the orientation of objects, the absolute speed and/or relative speed of objects, and the like. .

[063] It should be noted that the set of sensor systems 280 may include other types of sensor systems than those examples of which are described above without departing from the scope of the present technology.

[064] Lidar system

[065] In accordance with the present technology, as shown in FIG. 2, vehicle 220 is equipped with at least one light detection and ranging system, such as lidar system 300 (described in more detail below), to collect information about the environment 250 of vehicle 220. Although described here only in context installation on the vehicle 220, it is also contemplated that the lidar system 300 may operate stand-alone or connected to another system.

[066] Depending on the implementation, the vehicle 220 may contain more or less lidar systems 300 than shown in the drawings. Depending on the particular embodiment, the choice of sensor systems 280 may depend on the particular embodiment of the lidar system 300. The lidar system 300 may be installed on the vehicle 220 initially or retrofitted in various locations and/or configurations.

[067] For example, depending on the implementation of vehicle 220 and lidar system 300, lidar system 300 may be mounted on the inner top of the windshield of vehicle 220. However, as shown in FIG. 2, other mounting locations for lidar system 300, including the rear window, side windows, front hood, roof, front grille, front bumper, or side of vehicle 220, fall within the scope of the present invention. In some cases, the lidar system 300 may be located in a special housing mounted on top of the vehicle 220.

[068] In some non-limiting embodiments, such as those shown in FIG. 2, one of several lidar systems 300 is rotatably mounted on the roof of a vehicle 220. For example, lidar system 300 rotatably mounted on vehicle 220 may include some elements capable of rotating 360 degrees about the axis of rotation of lidar system 300. When rotatably mounted, lidar system 300 may collect data on most segments of the vehicle's environment 250. 220.

[069] In some non-limiting embodiments of the present technology, for example, as shown in FIG. 2, the lidar systems 300 are permanently mounted on the side or on the front grille. For example, a lidar system 300 mounted on a non-rotatable vehicle 220 may include at least some elements that are not capable of 360-degree rotation but collect data about predefined segments of the environment 250 of the vehicle 220.

[070] Regardless of the specific location and/or specific configuration of the lidar system 300, it collects data about the environment 250 of the vehicle 220, used, for example, to build a multidimensional map of objects in the environment 250 of the vehicle 220. The following describes in detail the design of lidar systems 300 to collect data about the environment 250 of the vehicle 220.

[071] In FIG. 3 is a diagram of one particular embodiment of a lidar system 300 implemented in accordance with some non-limiting embodiments of the present technology.

[072] In general, the lidar system 300 contains several internal elements, in particular, (1) a light source 302 (also called a laser source or a radiation source), (2) a beam splitter element 304 (also called a beam splitter), (3) a block 308 scanning unit (also called a scanner node or scanner unit), (4) a receiving unit 306 (also called a detection system, receiving node, receiving unit, or detector), and (5) a controller 310. In addition to the elements examples of which are listed above, it is contemplated that lidar system 300 may include multiple sensors (such as a temperature sensor, humidity sensor, etc.) that are not shown in FIG. 3.

[073] In some non-limiting embodiments of the present technology, one or more internal elements of the lidar system 300 are located in a common housing 330, as shown in FIG. 3. In some embodiments of the present technology, the controller 310 may be located outside the common housing 330, but associated with the elements located therein.

[074] According to non-limiting embodiments of the present technology, the lidar system 300 generally operates as follows. The light source 302 of the lidar system 300 emits a continuous laser beam in a narrow wavelength range. The fast switching module 390 splits the light from the light source 302 into short pulses for the first optical path, forming an output beam 314, and the light beam 315 formed from the residual light of the light beam (not split into pulses) is sent to the second optical path. The scanning module 308 scans the environment 250 of the vehicle 220 with the output beam 314 to detect or capture data of previously unknown objects (such as the object 320). Light reflected from unknown objects (such as object 320) is received by scan unit 308 and directed by scan unit 308 to detection unit 306 (through beam splitter 304), forming an input beam 316. Residual light beam 315 from fast switching module 390 over the second optical path is also directed to the beam splitter 304 and then to the detection unit 306 so that the beams 315, 316 form a combined beam 317. The detection unit 306 thus detects the combined beam 317, which is a coherent superposition of the residual light beam 315 (reference beam) and an input light beam 316 from the environment 250 (a signal beam carrying information about the environment 250). The electronic signals received by the controller 310 corresponding to the detected combined beam 317 are then used to determine the distance 318 to at least one object 320 to form a multi-dimensional environment map 250 where the objects (including the object 320) are represented as one or more data points. The operation of the lidar system 300 is described in more detail below.

[075] As some non-limiting examples, object 320 may be (in whole or in part) a person, a vehicle, a motorcycle, a truck, a train, a bicycle, a wheelchair, a stroller, a pedestrian, an animal, a road sign, a traffic light, lane marking, pavement marking, parking space, support, fence, road barrier, pothole, railroad crossing, obstacle on or near the road, curb, stopped vehicle on or near the road, light pole, house, building , trash can, mailbox, tree, any other road object, or any combination of two or more such objects or parts thereof.

[076] For example, object 320 is at distance 318 from lidar system 300. When output beam 314 reaches object 320, object 320 typically reflects and/or scatters at least a portion of the light from output beam 314 and some of the reflected and/or scattered light beams may be returned to the lidar system 302 where they may be received as an input beam 316. By reflection is meant that at least a portion of the light beam from the output beam 314 is reflected from the object 320. A portion of the light beam from the output beam 314 may be absorbed or scattered by the object 320.

[077] Details regarding the use and implementation of these elements of the lidar system 300 in accordance with some non-limiting embodiments of the present technology are described below.

[078] Light Source

[079] The light source 302 is connected to the controller 310 and emits light at a predetermined operating wavelength. To do this, in some non-limiting embodiments of the present technology, the light source 302 comprises at least one laser to operate at a given operating wavelength. As described in more detail below, the light source 302 in accordance with the present technology is a constant laser source 302, that is, the laser source 302 emits a continuous beam and is not a pulsed laser that is commonly used in time-of-flight lidar systems.

[080] The operating wavelength of the light source 302 may be in the infrared, visible, and/or ultraviolet portions of the electromagnetic spectrum. For example, the light source 302 may include at least one laser with an operating wavelength of approximately 650 nm to 1150 nm. Alternatively, the light source 302 may comprise a laser diode emitting light at a wavelength of about 800 nm to 1000 nm, about 850 nm to 950 nm, or about 1300 nm to 1600 nm.

[081] The light source 302 of the lidar system 300 is typically an eye-safe laser, or in other words, the lidar system 300 may be classified as an eye-safe laser system or laser product. In general, an eye-safe laser, laser system, or laser product can be a system with some or all of the following parameters: emission wavelength, average power, peak power, peak intensity, pulse energy, beam size, beam divergence, exposure time, and an output beam scanning scheme such that the light emitted by this system represents little or no chance of harming human eyes.

[082] According to some non-limiting embodiments of the present technology, the operating wavelength of the light source 302 may be in the region of the electromagnetic spectrum corresponding to sunlight. Therefore, in some cases, sunlight may act as background noise capable of drowning out the light signal detected by the lidar system 300. This solar background noise may lead to false detections and/or otherwise distort the measurements of the lidar system 300. Although in some In some cases it may be desirable to increase the signal-to-noise ratio (SNR) of the lidar system 300 by increasing the power level of the output beam 314, in some situations this may not be desirable. For example, in some cases it may be undesirable to increase the power of the emitted light to levels above an eye-safe threshold.

[083] In some non-limiting embodiments of the present technology, the light source 302 may comprise one or more laser diodes, including a Fabry-Perot laser diode, a quantum well laser, a distributed Bragg reflector (DBR) laser, a distributed feedback laser (DFB) or vertical cavity surface emitting laser (VCSEL), but not limited to. As examples, the laser diode in light source 302 may be an aluminum gallium arsenide (AlGaAs), indium gallium arsenide (InGaAs), or indium gallium arsenide phosphide (InGaAsP) laser diode, or any other suitable laser diode.

[084] In some non-limiting embodiments of the present technology, light source 302 emits a light beam as a collimated optical beam, but it is contemplated that the resulting beam may have any beam divergence suitable for a given application. In general, the divergence of an emitted light beam is an angular measure of the increase in the transverse dimension of the beam (e.g., beam radius or diameter) as light propagates from the light source 302 or lidar system 300. In some non-limiting embodiments of the present technology, the light beam may have essentially circular cross section.

[085] It is also contemplated that the light beam emitted by light source 302 may be unpolarized or randomly polarized, may not have a specific or fixed polarization (eg, its polarization may change over time), or may have a specific polarization (eg, output beam 314 can be linear, elliptical, or circularly polarized).

[086] Quick Switch Module

[087] In accordance with the present technology, the lidar system 300 in FIG. 4 includes a fast switching module 390 for modulating the light beam emitted by the light source 302. In particular, module 390 is capable of receiving a narrow wavelength continuous light beam from light source 302 .

[088] As briefly described above, the fast switching module 390 divides the continuous beam received from the light source 302 into two beams: an output beam 314 formed from pulses radiated in the first direction along the first optical path, and a residual beam 315, also referred to as here by the residual light beam 315, in which all the light not included in said pulses is directed in the second direction along the secondary optical path. The separation of the two beams 314, 315 is schematically illustrated in FIG. 4, where the power (P) of each of beams 314, 315 is given over a time period (T) of one pulse. The fast switching module 390 quickly switches between sending light as two beams 314, 315. It should be noted that the angle shown between the output beam 314 and the residual light beam 315, that is, between the first direction and the second direction, is only an illustrative example and does not imply restrictions.

[089] In some non-limiting embodiments, fast switching module 390 may be implemented as an acousto-optic modulator (AOM). In such an implementation, the modulator 390 quickly switches between transmitting pulses in the first direction and diffracting (using first order diffraction) the remaining light in the second direction. In some embodiments, the order of impulse beam 314 and residual beam 315 may be reversed. When using an acousto-optic modulator 390, the residual beam 315 receives a small frequency shift (on the order of tens of hertz). Thus, in at least some non-limiting embodiments of the present technology, the controller 310 can use the local oscillator detection method to determine the time-of-flight even for weak reflected signals, because in the detection unit 306, due to the small relative frequency difference between the emitted beams 314, 315 there will be a beat frequency signal component between the input beam 316 and the residual beam 315.

[090] In some non-limiting embodiments, fast switching module 390 may be implemented as an electro-optical modulator (EOM). In such implementations, the electro-optical modulator 390 may be located, for example, in one branch of a Mach-Zehnder interferometer with 2×2 switches. In some non-limiting implementations, the electro-optical modulator 390 is capable of rapidly switching the phase of the light beam from the laser source 302, and this phase change allows the light beam to be split into two interferometer paths. Thus, the pulses may be sent on the first path to form the output beam 314, and the residual light may be sent on the second path of the interferometer to form the residual beam 315.

[091] It should be noted that an electro-optic modulator does not typically initiate a frequency shift between beams 314, 315. Therefore, in some non-limiting embodiments implementing an electro-optic modulator, controller 310 may use a homodyne detection method where controller 310 detects a relative phase change between input beam 316 and residual beam 315. In some non-limiting embodiments, a balanced coherent detection mode may be implemented to help reduce noise, for example by using a secondary photodetector.

[092] In some non-limiting embodiments of the present technology, lidar system 300 may further comprise an optical amplifier to amplify output beam pulses 314.

[093] Beam splitter

[094] FIG. 3 depicts an optional beam splitter 304 located in housing 330. Beam splitter 304 is commonly known as a beam splitter, but in non-limiting embodiments of the present technology, it is used to combine input beam 316 (entering lidar system 300 from environment 250) with residual light beam 315 directed towards beam splitter 304 from fast switching module 390 into combined beam 317. Beam splitter 304 also directs combined beam 317 to detection unit 306 for further processing by controller 310.

[095] It should be noted that the beam splitter element 304 typically separates the intensity (optical power) of the radiation incident on it into two directions (or two fibers in the case of fiber optic splitters). In some non-limiting embodiments of the present technology, beamsplitter 304 thus forms two combined beams 317. According to the present non-limiting embodiment, only one combined beam 317 is used and further discussed. However, it is assumed that both the combined beams 317 can be used in the balanced detection method.

[096] Depending on the specific implementation, the beam splitter element 304 can evenly share the intensity of the light incident on it. In other non-limiting embodiments of the present technology, the beam splitter 304 may equally share the intensity of the output beam 314 between the scanning beam and the residual beam. For example, the beam splitter element 304 can direct up to 80% of the intensity of the light incident on it in the first direction, and the rest (up to 20% of the intensity of the incident light) in the second direction. In other non-limiting embodiments of the present technology, the beam splitter element 304 can change the split ratio of the light incident on it (eg, from 1% to 95% of the intensity of the light incident on it).

[097] Depending on the implementation of the lidar system 300, the beam splitter element 304 may be implemented in various forms, including a glass prism beam splitter element, a half-silver mirror beam splitter element, a dichroic mirror prism beam splitter element, and the like, but not limited to them. For fiber optic implementations of the lidar system 300, the beam splitter element 304 may be implemented as a fiber optic beam splitter, such as a 50/50 fiber optic beam splitter.

[098] Internal Beam Paths

[099] As schematically depicted in FIG. 3 and FIG. 4, lidar system 300 has a plurality of internal paths along which light beams propagate within lidar system 300. As mentioned above, laser light emitted by light source 302 is modulated by fast switching module 390 to create two beams, output beam 314 and residual beam 315. The output beam 314 is directed to a scan unit 308 (described in more detail below), which scans the field of view of the lidar system 300 with the output beam 314. input beam 316.

[0100] Next, the input beam 316 through the block 308 scanning and/or additional optical elements is directed through the beam splitter element 304 to the block 306 detection. In some implementations, lidar system 300 may have beam paths that direct input beam 316 directly from environment 250 to detection unit 306 (without passing input beam 316 through scan unit 308).

[0101] Residual beam 315 with residual light other than pulses is directed from fast switching module 390 to beam splitter 304 . Depending on the implementation, the residual beam 315 may be directed to the beam splitter element 304 directly (for example, over an optical fiber), or the lidar system 300 may contain additional optical elements to direct the residual beam 315 to the beam splitter element 304.

[0102] In the beam splitter element 304, the input beam 316 and the residual beam 315 are coherently superimposed on each other to form the combined beam 317. The detection unit 306 then receives the combined beam 317. It is contemplated that the combined beam 317 can be directed between the beam splitter element 304 and the detection unit 306 with additional optical elements.

[0103] Although only one of the beams 314, 315 is shown here emitting light at any time, it should be noted that interference from the combined beam 317 is possible in detection unit 306 due to the extra distance traveled by the output/input pulses. beams 314, 316 compared to the residual beam 315 (and hence the time taken).

[0104] It should also be noted that in various non-limiting embodiments of the present technology, a plurality of internal beam paths may comprise multiple optical elements. For example, lidar system 300 may include one or more optical elements that allow light to be adjusted, shaped, filtered, modified, deflected, and directed in lidar system 300, such as output beam 314 and/or input beam 316. In particular, lidar system 300 may contain one or more lenses, mirrors, filters (for example, bandpass or interference filters), optical fibers, circulators, beam splitters, polarizers, polarizing beam splitters, wave plates (for example, half-wave or quarter-wave plates), diffractive elements, microelectromechanical (MEM) elements , collimator elements or holographic elements.

[0105] It is contemplated that in some non-limiting embodiments of the present technology, one internal beam path and another internal beam path of the plurality of internal beam paths may share some common optical elements, however, this may not be implemented in every embodiment of the present technology. .

[0106] Scan unit

[0107] In general, the scanner 308 directs the output beam 314 in one or more directions to the environment 250. The scanner 308 is associated with the controller 310. The controller 310 is for controlling the scanner 308 to direct the output beam 314 in the desired direction and/ or according to a predetermined scanning pattern. In general, in the context of the present description, "scan pattern" may refer to the pattern or path along which the output beam 314 is directed by the scan unit 308 during operation.

[0108] In some non-limiting embodiments of the present technology, controller 310 initiates scanning by scan unit 308 using output beam 314 in multiple horizontal angle ranges and/or vertical angle ranges. The total scanning angle of the output beam 314 provided by the scan unit 308 is referred to here as the field of view. It is contemplated that the location, orientation, and/or angular ranges may be dependent on the particular implementation of the lidar system 300. The field of view typically includes several regions of interest, defined as portions of the field of view, which may contain, for example, objects of interest. In some implementations, scan unit 308 may provide further exploration of a selected region of interest 325. Region of interest 325 of lidar system 300 may refer to area, volume, area, angular range, and/or portions of the environment 250 where lidar system 300 may scan and/or capture data.

[0109] It should be noted that the location of the object 320 in the environment 250 of the vehicle 220 may partially or completely overlap, encompass, or be contained within the region of interest 325 of the lidar system 300.

[0110] It should also be noted that in accordance with some non-limiting embodiments of the present technology, the scanner 308 may scan the output beam 314 horizontally and/or vertically and, accordingly, the region of interest 325 of the lidar system 300 may have a horizontal direction and vertical direction. For example, the region of interest 325 may be defined by an angle of 45° in the horizontal direction and 45° in the vertical direction. In some cases, different scan axes may have different orientations.

[0111] In accordance with non-limiting embodiments of the present technology, in order to provide scanning of the output beam 314 of the area of interest 325, the scanning unit 308 includes a pair of mirrors (not shown separately), each of which is independently associated with a corresponding galvanometer (not shown separately), providing their management. The controller 310 initiates rotation of each pair of mirrors through the corresponding galvanometers around the corresponding one of the mutually perpendicular axes, scanning the area of interest 325 according to a predetermined scanning scheme.

[0112] In some non-limiting embodiments of the present technology, scanner 308 may further comprise a plurality of other optical and/or mechanical elements for scanning with output beam 314. For example, scanner 308 may include one or more mirrors, prisms, lenses, microelectromechanical elements, piezoelectric elements, optical fibers, dividers, diffractive elements, collimator elements, etc. It should be noted that the scan unit 308 may also include one or more additional actuators (not shown separately) that actuate at least some of the other optical elements, for example, to rotate, tilt, rotate or angle around one or more axes.

[0113] Thus, the lidar system 300 may use a predetermined scanning pattern to generate a point cloud generally covering the region of interest 325 of the lidar system 300. This point cloud of the lidar system 300 may be used to render a multidimensional map of objects in the environment 250 of the vehicle 220. B In some non-limiting embodiments of the present technology, a predetermined scan pattern for scanning a region of interest 325 may be associated with an appropriate scan rate.

[0114] Detection unit

[0115] According to some non-limiting embodiments of the present technology, the detection unit 306 is associated with the controller 310 and can be implemented in various ways. In accordance with the present technology, the detection unit 306 includes a photodetector 307, but may include, but is not limited to, a photodetector, an optical receiver, an optical sensor, a detector, an optical detector, optical fibers, and the like. As described in more detail below, in some non-limiting embodiments of the present technology, detector 306 acquires or detects at least a portion of combined beam 317.

[0116] In some non-limiting embodiments, the detection unit 306 may also include circuitry performing signal amplification, sampling, filtering, signal conditioning, analog-to-digital conversion, time-to-digital conversion, pulse detection, threshold detection, rising edge detection, detection falling edge, etc. For example, detection unit 306 may include electronics for converting a received photocurrent (eg, current produced by an APD diode in response to a received optical signal) into a voltage signal. Detection unit 306 may also include additional circuitry for generating an analog or digital output signal corresponding to one or more characteristics (eg, leading edge, trailing edge, amplitude, duration, etc.) of the received optical pulse.

[0117] Controller

[0118] Depending on the particular implementation, the controller 310 may include one or more processors, an application specific integrated circuit (ASIC), a programmable gate array (FPGA), and/or other suitable circuits. The controller 310 may also include a non-volatile computer-readable memory for storing instructions executed by the controller 310 as well as data that the controller 310 may generate based on signals received from other internal elements of the lidar system 300 and transmitted to other internal elements of the lidar system 300. The memory may contain volatile elements (eg RAM) and/or non-volatile elements (eg flash memory, hard drive). The controller 310 may collect data during operation and store it in memory. For example, such data generated by controller 310 may point to data points in the point cloud of lidar system 300.

[0119] It is contemplated that, in certain non-limiting embodiments of the present technology, controller 310 may be implemented similarly to electronic device 210 and/or computer system 100 without departing from the scope of the present technology. In addition to collecting data from the detection unit 306, the controller 310 can also provide control signals to the light source 302 and the scanner 308 and receive diagnostic data from them.

[0120] As mentioned above, the controller 310 is associated with the light source 302, the fast switching module 390, the scanning unit 308, and the detection unit 306. In some non-limiting embodiments of the present technology, controller 310 may receive electrical trigger pulses from fast switching module 390, where each electrical trigger pulse corresponds to light source 302 emitting an optical pulse. Controller 310 may further provide commands, a control signal, and/or a trigger signal to fast switching module 390 indicating when fast switching module 390 should generate optical pulses corresponding to, for example, output beam 314.

[0121] In addition, the controller 310 may send an electrical trigger signal including electrical pulses to emit light from the light source 302 in response to the electrical trigger signal. It is also contemplated that the controller 310 can cause the light source 302 to change one or more characteristics of the output beam 314 produced by the light source 302, such as frequency, period, duration, pulse energy, peak power, average power, and wavelength of the optical pulses.

[0122] In accordance with the present technology, the controller 310 allows to determine the value of "time of flight" for the optical pulse in order to calculate the distance between the lidar system 300 and one or more objects in the field of view, as briefly described above. The time-of-flight determination is based on time information associated with (1) a first time when an optical pulse (eg, output beam 314) is generated by fast switching module 390, and (2) a second time when a portion of the optical pulse (eg, from the input beam 316) has been detected or received by the detection unit 306 . In some non-limiting embodiments of the present technology, the first time may indicate the time when the controller 310 emits the corresponding electrical pulse associated with the optical pulse, and the second time may indicate the time when the controller 310 receives from the detection unit 306 an electrical signal generated in response to receiving a portion of the optical pulse from the input beam 316.

[0123] In accordance with the present technology, the controller 310 determines when the reflected pulse from the input beam 316 reaches the detection block 306, using coherent detection (heterodyne detection or homodyne detection) to extract the pulse from the combined beam 317. Thus, even weak reflected or scattered pulses can be detected in high noise input beam data. Specific methods and calculations for coherent (heterodyne or homodyne) detection are known in the art and their detailed description is omitted here.

[0124] In accordance with the present technology, the controller 310 is able to determine, based on the first time and the second time, the time-of-flight and/or the phase shift values of the emitted pulse of the output beam 314. The time-of-flight T , in a certain sense, is the travel time of the radiated pulse in both directions required to fly from the lidar system 300 to the object 320 and back to the lidar system 300. Thus, the controller 310 allows you to determine the distances 318 in accordance with the following equation:

, (1)

, (1)

where D is the distance 318, T is the value of the time of flight, c is the speed of light (approximately 3×10 ⁸ m/s).

[0125] As previously mentioned, the lidar system 300 can be used to determine the distance 318 to one or more other potential objects located in the environment 250 of the vehicle. By scanning the output beam 314 to a given region of interest 325 of the lidar system 300 in accordance with a predetermined scanning pattern, the controller 310 determines distances (similar to distance 318) to the corresponding data points in the region of interest 325 of the lidar system 300. Thereafter, the controller 310 typically provides sequential capture of these points (for example, point clouds) as a multidimensional map. In some implementations, data related to specific time-of-flight and/or distances to objects may be represented in different data formats.

[0126] The multidimensional map may be used by the electronic device 210 to detect or otherwise identify objects, or to determine the shape or distance of potential objects within the region of interest 325 of the lidar system 300. It is contemplated that the lidar system 300 is capable of repeatedly or iteratively capturing and/or generating point clouds at any speed suitable for a given application.

[0127] Lidar system control method

[0128] In FIG. 6 is a flow diagram of a method 500 for controlling lidar system 300. Method 500 is described in detail below in accordance with non-limiting embodiments of the present technology.

[0129] In some non-limiting embodiments of the present technology, method 500 may be implemented by controller 310 associated with lidar system 300. As discussed previously, in at least some non-limiting embodiments of present technology, controller 310 may comprise one or multiple processors and may be implemented similarly to electronic device 210 and/or computer system 100 without deviating from the scope of the present technology. Implementation of method 500 begins at step 510.

[0130] Step 510: initiating the laser source to emit a light beam in a narrow band.

[0131] In step 510, the controller 310 provides commands, a control signal and/or a trigger signal to the light source 302, indicating that the light source 302 should emit light in the narrow band, that is, with a small bandwidth of wavelengths, in the direction of the block 308 scans. As mentioned above, in the present technology, the light source 302 is a laser source 302. The laser source 302 produces a light beam with a substantially constant output power.

[0132] Step 520: controlling the fast switching module to modulate the amplitude of the emitted light beam - providing short pulses in the first direction and residual light in the second direction.

[0133] In step 520, the controller 310 controls the fast switching module 390 to modulate the amplitude of the light generated by the laser source 302 to emit light in two directions. The fast switching module 390 outputs a series of short pulses to form the output beam 314 in the first direction and directs the residual light beam 315 in the second direction to the beam splitter element 304. In specific non-limiting embodiments, the first and second directions may have any relative position, without being limited to option shown in the drawings. For example, in some non-limiting embodiments, beams 314, 315 may be emitted parallel to each other and then directed into fiber optic elements. In some non-limiting embodiments, controller 310 may control the duration and/or frequency of output beam 314 pulses.

[0134] Step 530: Initiating the emission of short scanning light pulses by the scanner from the system towards surrounding objects.

[0135] In step 530, controller 310 controls scan unit 308 to emit output beam 314 in the form of laser pulses outward into environment 250. The scanning scheme and frequency depend on the particular embodiment of scan unit 308, as well as the duration and frequency of output beam 314 pulses.

[0136] Step 540: receiving electronic signals from the detection unit receiving the combined signal of the residual light of the light beam and the reflected signal from the surrounding objects.

[0137] At step 540, the controller 310 receives electronic signals from the detection unit 306 corresponding to the detection of the combined beam 317. The input beam 316 is directed by at least the scanning unit 308 to the beam splitter element 304 . In the beam splitter element 304, the input beam 314 and the residual light beam 315 are combined and the combined beam 317, which is directed to the photodetector 396 of the detection unit 306. As mentioned above, photodetector 396 is a quadratic photodetector for detecting linear superposition of waves of two beams 316, 317. Thus, controller 310 receives electrical signals at least including a DC signal associated with the sum of beams 316, 317 and an AC signal corresponding to the product electric fields of rays 316, 317.

[0138] Step 550: determining the distance to at least one of the surrounding objects based on the time-of-flight calculated by processing the electronic signals obtained from the combined signal.

[0139] In step 550, the controller 310 determines (or calculates) the distance 318 to at least one object 320. The controller 310 determines the time of flight of one or more pulses of the output beam 314, exiting the lidar system 300, reflected from at least one object 320 and reaching the detection block 306 .

[0140] As mentioned above, the controller 310 determines the time-of-flight based on the electrical signals in the optical interference of the combined beam 317 at the photodetector 396 using a heterodyne detection technique. In some non-limiting embodiments of method 500, controller 310 may use homodyne detection techniques. It is also contemplated that, in some non-limiting embodiments, method 500 may include the use of additional photodetectors for time-of-flight determination by balanced coherent detection.

[0141] Those skilled in the art will appreciate that some embodiments of the present technology may be directed to expanding the arsenal of technical solutions to a specific technical problem, namely, improving the quality of weak signals in a lidar system while limiting the light source output power of the lidar system.

[0142] For a person skilled in the art, possible changes and improvements to the above-described embodiments of the present technology may be obvious. The foregoing description is for illustrative purposes only and is not intended to limit the scope of the invention. The scope of protection of this technology is determined solely by the scope of the appended claims.

[0143] Although the embodiments described above are given with reference to specific steps performed in a certain order, it should be understood that some of these steps can be combined, separated, or that their order can be changed without deviating from the present technology. . Accordingly, the order and grouping of steps is not limiting to the present technology.

Claims (21)

1. Time-of-flight lidar system comprising: - a laser source configured to emit a light beam in a narrow band; - an optical module placed with the ability to receive a light beam from a laser source and modulate the amplitude of the light beam for radiation short pulses of the light beam along the first optical path and residual light of the light beam through the second optical path; - a scanning unit located on the first optical path and configured to scan with short pulses of a light beam in the direction from the system to the surrounding objects; - at least one optical element configured to combine into a combined signal the residual light beam on the second optical path and the reflected signal reflected into the system from surrounding objects; - a detection unit configured to receive the combined signal; And - a controller communicatively connected to the detection unit and configured to process electronic signals from the detection unit obtained from the combined signal and determine the distance to at least one of the surrounding objects based on the time of flight calculated when processing the electronic signals received from combined signal. 2. The system of claim. 1, in which at least one optical element is a beam splitter. 3. The system of claim 1 wherein the optical module is an acousto-optic modulator (AOM). 4. The system of claim. 3, in which the controller is configured to determine the time of flight method of heterodyne detection. 5. The system according to claim 1, which is a fiber optic system, wherein at least one optical element is a fiber optic splitter. 6. The system of claim. 1, in which the detection unit contains a photodetector connected with the possibility of communication with the controller. 7. The system of claim. 1, in which the detection unit includes a first photodetector and a second photodetector, each of which is configured to receive at least a portion of the combined signal. 8. The system of claim. 1, further comprising an optical amplifier functionally located between the optical module and the scanning unit and configured to amplify the intensity of short pulses of the light beam. 9. The system of claim 1 wherein the optical module is an electro-optical modulator (EOM). 10. A method for controlling an optical system, including: - initiation by the controller of the emission of a laser source of a light beam in the narrowband range; - controlling the controller of the optical module to modulate the amplitude of the emitted light beam in at least two directions - short pulses of the light beam and residual light of the light beam; - initiation by the controller of the emission by the scanning unit of short pulses of the light beam in the direction from the system to the surrounding objects; - receipt by the controller of electronic signals from the detection unit, which receives the combined signal, which is a combination of the residual light of the light beam and the reflected signal reflected into the system from surrounding objects; And - determination by the controller of the distance to at least one object from the surrounding objects based on the time of flight calculated by processing the electronic signals obtained from the combined signal. 11. The method according to claim 10, characterized in that the control of the optical module comprises the control of the controller of the acousto-optic modulator. 12. The method of claim 10, wherein determining the time-of-flight by the controller includes determining the time-of-flight by a heterodyne detection method. 13. The method of claim 10, further comprising causing the controller to amplify the intensity of short pulses of the light beam by an optical amplifier operatively located between the optical module and the scan unit.

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